| 摘要 |
1,222,984. Unsaturated carboxylic esters. SOC. ITALIANA RESINE S.p.A. 10 April, 1968 [29 April, 1967], No. 17390/68. Heading C2C. [Also in Division B1] Acyclic unsaturated monocarboxylic esters are prepared by contacting a gaseous mixture of an olefin and oxygen or a molecular oxygencontaining gas with an aqueous carboxylic acid solution of a catalytic mixture of carboxylate and/or chloride salts comprising a copper salt and a palladium salt, the chloride content of the catalytic mixture being 0À5 to 3À0% by weight, removing a part at least of said solution containing the exhausted catalytic salts, and returning it to the reaction zone after regeneration by first distilling off the carboxylic acid, adding an aqueous alkaline carbonate to the distillation residue until a pH of between 8 and 8À5 is obtained, separating the insoluble metal carbonates and converting them to chlorides by means of hydrochloric acid. The catalytic mixture may also contain an alkali metal or alkaline earth metal salt. |
